SCX2_ISOMC
ID SCX2_ISOMC Reviewed; 68 AA.
AC P0DJK8;
DT 03-APR-2013, integrated into UniProtKB/Swiss-Prot.
DT 03-APR-2013, sequence version 1.
DT 03-AUG-2022, entry version 21.
DE RecName: Full=Beta-toxin Im-2;
OS Isometrus maculatus (Lesser brown scorpion) (Scorpio maculatus).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Isometrus.
OX NCBI_TaxID=497827;
RN [1]
RP PROTEIN SEQUENCE, FUNCTION, BIOASSAY, AND MASS SPECTROMETRY.
RC STRAIN=Ishigaki Island; TISSUE=Venom;
RX PubMed=23132570; DOI=10.1271/bbb.120438;
RA Ichiki Y., Kawachi T., Miyashita M., Nakagawa Y., Miyagawa H.;
RT "Isolation and characterization of a novel non-selective beta-toxin from
RT the venom of the scorpion Isometrus maculatus.";
RL Biosci. Biotechnol. Biochem. 76:2089-2092(2012).
CC -!- FUNCTION: Beta toxins bind voltage-independently at site-4 of sodium
CC channels (Nav) and shift the voltage of activation toward more negative
CC potentials thereby affecting sodium channel activation and promoting
CC spontaneous and repetitive firing (By similarity). Is toxic to both
CC insect and mammals. Induces paralysis in Acheta domestica crickets, but
CC does not induce death, whereas intracerebroventricular injection into
CC mice causes immediate death (at a dose of 0.05 ug/g). {ECO:0000250,
CC ECO:0000269|PubMed:23132570}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to
CC antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
CC {ECO:0000305}.
CC -!- MASS SPECTROMETRY: Mass=7909.7; Method=Electrospray; Note=Monoisotopic
CC mass.; Evidence={ECO:0000269|PubMed:23132570};
CC -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR AlphaFoldDB; P0DJK8; -.
DR SMR; P0DJK8; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0006952; P:defense response; IEA:InterPro.
DR CDD; cd00107; Knot1; 1.
DR Gene3D; 3.30.30.10; -; 1.
DR InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR InterPro; IPR003614; Scorpion_toxin-like.
DR InterPro; IPR036574; Scorpion_toxin-like_sf.
DR InterPro; IPR018218; Scorpion_toxinL.
DR InterPro; IPR002061; Scorpion_toxinL/defensin.
DR Pfam; PF00537; Toxin_3; 1.
DR PRINTS; PR00285; SCORPNTOXIN.
DR SMART; SM00505; Knot1; 1.
DR SUPFAM; SSF57095; SSF57095; 1.
DR PROSITE; PS51863; LCN_CSAB; 1.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Neurotoxin; Secreted; Toxin; Voltage-gated sodium channel impairing toxin.
FT CHAIN 1..68
FT /note="Beta-toxin Im-2"
FT /id="PRO_0000422067"
FT DOMAIN 1..67
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 15..66
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 19..40
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 26..47
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 30..49
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ SEQUENCE 68 AA; 7922 MW; F827102146E43B1B CRC64;
KDGYPMVRAG REKGCKIWCV INNESCDSEC KIRKGKKGYC YFWKLACYCE GLPANEQVWT
YEKNTCKP
